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Tick infestations are killing off moose calves in northeastern U.S.

Researchers from the University of New Hampshire tracked 179 nine- to 10-month-old moose calves through the winter and found that 70 per cent of the calves were dying over a three-year period. (Dan Bergeron/ N.H. Fish and Game Dept)

Tick infestations are killing moose calves in the northeastern U.S. at an alarming rate and climate change is to blame, according to a recent study.

The dead moose calves with pale or missing patches of fur, drained of their blood from parasitic winter ticks, are part of a phenomenon known as "ghost moose" which affects young and old, but with far more devastating consequences for calves.

In a study recently published in the Canadian Journal of Zoology, researchers from the University of New Hampshire tracked 179 nine- to 10-month-old moose calves in New Hampshire and Maine through winter and found that 70 per cent of the calves were dying over a three-year period.

Pete Pekins is a professor of wildlife ecology at the University of New Hampshire and the lead researcher on the winter ticks and moose research.

"Anything that's dependent on ambient temperature is going to be the most affected by slight changes in temperature and in slight changes in season," he said.

"In this case, that tick is a parasite that's given more time to find a host. Moose are just exposed to this potential parasite load for a longer period of time."

A study by the University of New Hampshire found moose calves had an average infestation of more than 40,000 winter ticks. (Dan Bergeron/ N.H. Fish and Game Dept)

Calves had an average infestation of more than 40,000 winter ticks.

The ghost moose appearance is a result of hordes of clustering winter ticks feasting on the animals resulting in anemia, lethargy and death.

"What happens to these animals is their body is responding trying to produce blood," said Pekins. "They have to replace it."

But the moose diet consists of virtually zero protein to compensate for the loss, leading to death.

About the Author

Rhiannon Johnson is an Anishinaabe journalist from Hiawatha First Nation based in Toronto. She has been with the Indigenous unit since 2017 focusing on Indigenous life and experiences throughout Ontario. You can reach her at rhiannon.johnson@cbc.ca and on Twitter @rhijhnsn.